Utica Boilers UB90-100 インストール手順

K.  Reinstall burner and mixer gasket and position 

mixer assembly over studs. Install fi ve (5) nuts but 

do not tighten. Reinstall igniter and igniter gasket 

and fasten with two (2) screws. Use care when 

installing the igniter. Tighten fi ve (5) nuts holding 

mixer assembly.

L. Connect:

• Gas line to gas valve
• Condensate drain line to boiler 
• Pressure switch hose to gas valve
• Air by-pass to mixer
• 1 ½” x 2” fl exible coupling to air inlet and make 

sure to put air baffl e back to correct position

• Igniter wires 
• Gas valve wires 

Visually inspect condensate lines leading from boiler 

sections and vent pipe connector to condensate trap. 

Refer to repair parts diagrams. Any foreign material or 

debris visible in condensate lines needs to be cleaned 

out as follows: 

A.  Disconnect condensate drain lines from condensate 

trap.

B.  Remove condensate trap and drain all water from 

trap.

C.  Disconnect condensate lines from fi tting on bottom 

of boiler and vent pipe connector.

D.  Run cold water through condensate lines and trap 

to thoroughly fl ush out any sediment or debris.

E.  Reinstall condensate trap and condensate lines.
F.  Follow instructions under “Near Boiler Piping” for 

fi lling condensate trap with water.

Inspection of fl ue connector requires following steps. Refer 

to repair parts diagram.

A.  Loosen the clamp on the draft inducer end of the 

2” vent pipe connector that connects the vent 

to the draft inducer. Disconnect (unplug) wiring 

harness from draft inducer motor and draft inducer 

temperature safety switch. Remove four (4) bolts 

that attach draft inducer to fl ue connector.

B.  Remove draft inducer and gasket from top of fl ue 

connector.

C.  Inspect interior of fl ue connector. Any buildup of 

sediment or aluminum oxide on inside surface must 

be cleaned. Position draft inducer gasket and draft 

inducer and fasten with four (4) screws. Be sure to 

connect ground wire from draft inducer motor to 

one of four mounting screws.

D.  Connect wiring harness leads to draft inducer motor 

and draft inducer temperature safety switch.

E.  Connect vent pipe connector to draft inducer outlet.

Before servicing, turn off electrical power to boiler 

at service switch. Close manual gas valve to turn 

gas supply OFF to boiler. Failure to comply will result 

in death or serious injury.

  

Have qualifi ed service agency perform the following 

service procedures. Boiler owner should not attempt 

these procedures.

Before Servicing, turn off electrical power to boiler at 

service switch. Close manual gas valve to turn off gas 

supply to boiler.

Cleaning Flue passages between boiler sections. 

A.  Any buildup of sediment or aluminum oxide (white 

powdery or fl aky substance) in fl ue passages must 

be cleaned as follows.

B.  Remove jacket front and top panels. Disconnect 

condensate drain line from barbed fi tting on bottom 

of boiler. Keep open end of drain line above water 

level in condensate trap to prevent trap from 

draining. Disconnect pressure switch hose from 

barbed fi tting on gas valve. Disconnect 1½ x 2” 

fl exible coupling from air inlet. Disconnect air by-

pass (½” transparent vinyl tube) from bottom of 

mixer.

C.  Remove air baffl e from ½” x 2” fl exible coupling 

and clean air baffl e if necessary. Refer to repair 

parts diagram, mixer and pressure switch 

assembly.

D. Confi rm manual gas valve is closed and disconnect 

gas line to gas valve at union. Disconnect wires to 

gas valve and igniter.

E.  Loosen but do not remove fi ve (5) nuts attaching 

mixer assembly to boiler. Remove two (2) igniter 

screws and remove igniter. 

F. Remove 

fi ve (5) nuts and remove mixer assembly. 

Remove burner and mixer gasket.

G.  Aluminum oxide deposits are water soluble and 

may be rinsed away with spraying or running 

water. Before rinsing, connect a ½” I.D. hose to 

barbed fi tting on bottom of boiler and run hose to 

bucket or drain.

H.  After rinsing, remove any remaining loosened 

sediment using shop vacuum with snorkel 

attachment.

I.  Inspect burner for any foreign matter in fl ame 

ports or inside burner. Any foreign matter should 

be removed by blowing with compressed air or 

vacuuming.

J.  Inspect interior of mixer for any signs of sediment 

or aluminum oxide and clean if necessary.

Verify proper operation after servicing.